LASER SURFACE-TREATMENT

Experimental procedures and current state-of-the-art are presented for laser surface treating methods such as alloying, cladding, grain refining, and transformation hardening using a cw CO//2 laser. Microstructural and x-ray analyses of the treated surfaces indicate that a laser beam can locally enhance surface properties. Laser alloying offers the possibility to modify a low cost workpiece surface so that it has the desired high quality surface properties characteristic of high performance alloys. Laser cladding offers feasibility to apply high melting cladding alloys on low melting workpieces, to reduce the amount of dilution of cladding alloy with the workpieces, and the potential to apply dense ceramic claddings to metallic workpieces. Laser grain refining offers potential to minimize or eliminate surface defects such as inclusions, intermetallic compounds, and pores, and to provide a refined grain structure. Laser transformation hardening provides the treated workpieces with a hard martensitic surface that has compressive stresses for enhanced fatigue life, and reduction in wear rate of treated surfaces is achieved. This study indicates that the use of lasers for surface treatment has several limitations.